函数

fn gcd(a: u32, b: u32) -> u32 {
    if b > 0 { gcd(b, a % b) } else { a }
}

fn main() {
    dbg!(gcd(143, 52));
}

This slide should take about 3 minutes.

类型跟随在声明的参数后（与某些编程语言相反），然后是返回类型。
The last expression in a function body (or any block) becomes the return value. Simply omit the ; at the end of the expression. The return keyword can be used for early return, but the “bare value” form is idiomatic at the end of a function (refactor gcd to use a return).
Some functions have no return value, and return the ‘unit type’, (). The compiler will infer this if the return type is omitted.
Overloading is not supported – each function has a single implementation.
- 始终采用固定数量的参数。不支持默认参数。宏可用于支持可变函数。
- Always takes a single set of parameter types. These types can be generic, which will be covered later.

Comprehensive Rust 🦀